Method of making channel strips



1933- J. l. TAYLOR METHOD OF MAKING CHANNEL STRIPS Original Filed May18, 1928 2 Sheets-Sheet l JUL/Fh/UE jbs'sph 7757/02? flu 2 3 Oct. 17,1933. J. TAYLOR IETHOD OF MAKING CHANNEL STRIPS Original Filed May 18,1928 2 Sheets-Sheet 2 Patented Oct. 17,

UNITEDVS'FATES 1,931,333 i METHOD OF MAKING CHANNEL STRIPS Joseph 1.Taylor, Ridgewood, N. J., assignor to The B. F. Goodrich Company, NewYork, N. Y., a corporation of New- York 1 Original application May 18,1928, Serial No.

Divided and this applicationAugust 14, 1930. SerialNo. 475,333

Claims. (01. 18-59) This inventionis a division of my copending'application Serial No. 278,887 filed May 18, 19 28, and relates tochannel strips such as are used as glass-run channels in the windows ofautomobiles to cushion and seal the margins of the window glass slidablymounted therein or other articles of rubber having a fibrous coverthereon and to methods of making such strips.

My chief objects are moderate cost, lightness,

avoidance of noise, high cushioning, and sealing properties anddurability in such strips. More specific objects are to provide for theconvenient and satisfactory employment of sponge rubber as a cushioningelement in such a strip, preferably without preforming the sponge rubberas such or vulcanizing it prior to-its association with other elementsofthe strip, which heretofore has been considered necessary su fer as Iam aware; to

- provide for progressively forming the strip as the rubber elementthereof is continuously drawn from a calender in which it is prepared;to provide economyin'the'shapingand in the vulcanizingv of the strip;and to provide an accurately shaped channel strip comprising spongerubber without vulcanizing the strip or the sponge rubber elementthereof under pressure in a mold completely confining the strip. t i

Of the accompanyingdrawing's: Fig. '1 is a diagrammatic view of acalender and associated apparatusembodying and adapted for the practiceof my inventionlinits preferred form. Fig.2 is a section online 2.20fFig.1.

Fig. 3 isa section on line 3--3-0f Fig. 1.

I Fig. 4 is a section on line 4-4 of Fig, 1. Y Fig.5 is asection on line5-5 of Fig. 1,1" "Fig. 6 is asection on line 6--6 of Fig. 1.

Fig. 7 is an elevation, withparts sectioned and broken awayfofvulcanizing apparatus adapted for the practice of my invention. t

Fig. 8 is a perspective view of a work,.-h'ol,ding tray constituting apart of the apparatus of Fig. 7, with the work therein, partsbeinglsectioned and broken away. "Q l t f Fig. 91s a perspective view ofa piece of the finished product. I

Referring to the drawings, the finishedstrip (Fig.' 9) cox'riprises achanneled or U-shaped cushion body 10 of sponge rubber, a reinforcingstrip 11, preferably of squarewoven fabric, extending across the baseand into the legs pr the U-shaped sponge-rubber body, a decorative'andanti-friction covering' strip 12, preferably of felt, constituting alining for the interior of the sponge-rubber channel and extendingoutward;

onto the outer faces of the legs and terminating flush with the baseofthe sponge-rubber body, and a stiff foundation or backing strip 13-,pref! erably of a fibrous rubber composition, which is wider than and isapplied to the base of the chan-. nel structure just described, to givethe product longitudinal stiffness and inextensibility and: to providean anchorage flange on each side ofthe base of the structure. All of theelements de-..- scribed are preferably secured together by vul-'caniz'ation.

In the production of sponge rubber it hasbeen considered necessary toconfine the composition quite positively during the vulcanization, as byvulcanizing it. in a closed, rigid mold in order to'preventnon-uniformity in the cellular charac-. ter of .the product as theresult of excess :expan-. sion of the generatedgases, in some parts ofthe mass or collapse of some of the cells formed by the gas, and also itis desirable to employ, in vulcanizing a sponge-rubber composition in amold, a porous mold structure such as to permit the generated gases ,toescapefrom the cellsformed in the surface region ofi the mass andthusto. provide acontinuous and smooth but thin skin ofjdense,non-cellular. rubber at the; surface of the sponge-rubber body, as,distinguished from a product vulcanized in contact with. an imperviousmold surface and conse-"r quently having cells. open to its surface.

I find that the surface skin .of non-cellularrubber also is desirable"in the case of the sponge rubber body 10 vulcanized to the felt coveringtime provide a suflicient confinement or restraint of "the sponge-rubbercompound to prevent ,uni equal blowing. or distortion of thespongerubber mass when the assembly shown in Fig. Q isvulcanized in onlysuch confining' meansv as the open tray illustrated in Fig. 8,.asdistin-.. guished from the usual closed mold'confining the. article bycontact with its entire surface,,when the parts are accuratelyassembled, by the pro-.- cedure illustrated in Figs. 1 to 6, in therelationship in which they are there shown, the sponge- 5 rubbercomposition 10 being calendered; onto,

the cover strip, 12 and the reinforcing. strip 11,. and the base strip13 being adde'd'and thewhole structure being brought. substantially to,its final form, except for the expansion or blowing of 110 sponge-rubbercomposition, before the vuleffect upon the fibers of the felt cover 12.

order to avoid such effect and at thesame time ing medium.

terior of the air-circulating system. I

important to bring the stock to vulcanizing temand the base strip 13,bridging the groove, sufficiently confine the sponge-rubber of the stripduring vulcanization, when the parts are accurately assembled in therelation shown in Figs. 6 and 9, to provide accuracy'of form anduniformity of the cellular condition in the vulcanized product. Themember 14 conveniently may be made of bent sheet metal and may be fittedinto a metal pan 18 for strength of the assembly.

The vulcanization is conveniently efiected by mounting a number of thetrays with the work therein upon a vulcanizer car 19 (Fig. '7),placing'the car in a. vulcanizing chamber 20 provided with circulatingmeans such as the conduits .21, 22, and blower .23'and heating meanssuch as the steamcoil 24 for a fluid vulcanizbe of 1 a moist characterin order thatthe rubber, composition,including a blowing ingredient,which preferably is sodium bicarbonate 10% and ammonium carbonate 2 byweight in a composition containing 36% of rubber, will properly sponger, .blow as an incident of the vulcanization,.but I have found that whensteam or air approximately saturated with steam is employed. it resultsin a harmful loosening .In

obtain a proper sponging of the rubber composition'I preferably employair primarily as thevulcanizing medium and provide only a'moderateamount of moisture in it, as by providing one or more vents, such asthose affordedby the vent nipples 25, .25, from the steam coilv24 to thein- It is also perature rapidly in order to obtain a proper 'sponging ofthe rubber.

.The strip elements of Fig; 9, for the best adhesion and accuracy ofform, require to be' assembled by progression longitudinally of the Jstrip, and the preferred procedure and apparatus for so assembling .themare shown in Figs. 1 too.

As there shown a plurality of. strips of the covering felt 10 in flatfo'rm'are drawn from respective supply rolls 26, 26 through a calender1, 27. and in passing through the calenderireceiv'e upon their upperfaces respective coatings or face layers of the sponge-rubbercomposition 10 in'unvulcanized and non-cellular condition, theintervening strips of rubber composition 28, 28' on..the middle calenderroll passing back into the'stock bank 29.

From stock rolls '30, the reinforcing strips 11," 11, preferablyrubberized with a non-blowing composition; are drawn intoprogressivecontact I with the middlezone'of the rubber-coated upperfaces of the respective cover strips 10 and are progressively pressedthereagainst' by a pair of pinch rolls'31,"32 between which thecomposite strip is drawn.

The .upperpinch roll, 32, is shorter than the lower roll 31 and isformed at its ends with respective scoring flanges 33, 33 adapted toscore the layer of rubber'composition 10, as shown clearly in Fig.'2, tofacilitate the folding ofjthe The cover It is desirable thatrthemediumcoated strip along determinate longitudinal lines of fold such that eachside margin of the coated strip will be overlapped upon the adjacentside margin of the reinforcing strip '11, as is clearly shown in Fig. 3.I

For so folding the composite strip the. strip is drawn from the pinchrolls 31, 32 through a folding sleeve 34 of suitable form.

'As the folded composite strip passes from the folding sleeve 34 thebase strip 13, drawn from a supply r011 35, is progressively pressedonto the base side of-the strip assembly bythe passage ,of the basestrip and the assembly between a pair of pinch rolls 36, 37. The lowerpinch roll 37 is shorter than the upper roll 36 and is formed at itsends with respective scoring flanges 37 37 adapted to press groovesinthe under face of the composite strip, as shown clearly in Fig. 4, and,in coaction with the contact of the base strip 13 with the inwardlyfolded margins of the cover strip 12, to initiate a downward folding ofthe side margins or leg portions of the structure, such downward foldingof the leg portions then. being completed by a folder 38 ofsuitable'form comprising an anvil portion 39 fitting within the channelof the strip and extending beyond the rest of'the folder to serve as abacking for the legs of the strip against the force of a pair of rollers40, 40 mounted on vertical axes and adapted to'compact the respectivelegs of the channel strip against the anvil member as the strip is drawnforward between them.

As the strip passes'farther forwardgthe base of the structure, nowincluding the base strip 13, is further compacted by being passedbetween a pair of pinch rollers 41, 42, the lower roller 41 running inthe channel of the'strip.

As the compacted strippasses from these rolls it is cut into suitablelength for mounting in trays such as that shown in Fig. 8, as by meansof apair of suitably mounted and timed shear blades 43, 44. The trayspreferably are of such length as to be adapted for strips cut to thefinal length for use. Such lengths are thenmount'ed' in the trays andvulcanized as above described, which results in a product such as isshown in Fig.

I 9, the rubber composition 10 swelling and becoming, cellular-duringvulcanization, with good adhesion to the associated elements of thestrip and with a substantially uniform anddesirable cross- '2 sectionalform therein. The cover strip initially may be rubberized'with anon-blowing rubber compositionor-only with the sponge-rubber composition10. Asits edge faces, 'arenot strongly adhesive to the base strip 13 themargins of the cover strip move outward with' t he swellingsponge-rubber composition to'the extent permitted by the walls of thegroove ,of the tray in' which thestrip is mounted, giving the desiredbase structure for the legs of the channel stripes shown inFig. 9. ,f"Thereinforcing strip 11 stabilizes the legs of the channel in theirconverging relation to each: other by providing a comparatively stiffbase portion in each leg and by firmly anchoring each leg at the middle.of its base portion to the base strip 13, and at the same time permitsthe outer margin of the legs to serve effectively as soft and flexiblecushioning members. The reinforcing strip 11 also adheres strongly to;both the sponge rubber'body and the base strip 13 and thus provides awell bonded structure.

4 Various modifications are possible within the I claim:

1. The method of making a channel strip'of rubber with a fibrouscovering sheet thereon which comprises coating the fibrous sheet with anunvulcanized sponge-rubber composition, progressively applying a fabricreinforcing strip to the middle zone of the coated side of a coveringstrip of the coated sheet, progressively folding over the side marginsof the covering strip into overlapped relation to the reinforcing stripand thereby bringing coated surfaces of the covering strip together,progressively bending the resulting composite strip to channel form withthe covering strip extending throughout the interior surface of thechannel thereof, applying a relatively stiff strip of material to theexterior of the base of the channel structure, and subjecting thecompleted strip to vulcanizing heat without suchrconfinement as to causethe confining means to limit the volume increase of the sponge rubbercomposition.

2. The method of making an article comprising sponge rubber and afibrous cover thereon which comprises associating the fibrous coveringmaterial with a mass of unvulcanized spongerubber composition andsubjecting the resulting structure to vulcanizing heat in moist airwithout such confinement as to cause the confining means to limit thevolume increase of the structure.

3. The method of making a channel strip comprising sponge rubber whichcomprises forming a channel-shaped strip of unvulcanized vspongerubbercomposition in association with a reinforcing strip of fabric extendingacross the middle zone of the base of the channel and having its sidemargins extending into the respective. legs of the channel, applying'astiffening strip to the base of the structure, and subjecting theassembly to vulcanizing heat. 7

4:. The method of making a channel strip comprising rubber whichcomprises forming a channel-shaped strip of unvulcanized rubbercomposition in association witha reinforcing strip flexible coveringmaterial thereon, comprising,-

forming a blank by associating a strip of covering material with a stripof unvulcanized spongerubber' composition, so that the edges of thecovering material are spaced apart to expose a central portion of thesponge-rubber composition, applying a backing strip to said exposedcentral portion of the unvulcanized sponge-rubber composition,positioning the resulting blank in a mold so that the blank is ofsubstantially channel shape in cross-section with the backing memberforming the base of the channel and the portion having the coveringmaterial thereon forming the legs of the channel and then subjecting theblank to vulcanization to cause the sponge-rubber composition to expandand form the articleto the final desired channel-shape.

JOSEPH I. TAYLOR.

